Adhesive-free testing device and method for rock direct tensile test

Abstract

The invention provides an adhesive-free testing device and method for a rock direct tensile test. The adhesive-free testing device comprises an external support and an internal support, wherein the external support and the internal support are sheathed together through an internal support strut mounting hole and an internal support strut; the invention further provides an adhesive-free testing method for rock direct tensile test; the defects that by using the existing experimental method and due to strong rock crispiness, the connection test is fail by adopting the adhesion manner due to pooradhesion intensity, uneven adhesive thickness or end falling; a crispy material test piece is fixedly arranged through an upper base and a lower base without the need of high-intensity adhesive adhesion, in application of pressure, the internal support and an upper pull head are fixed, the external support moves downward to drive a lower pull head to directly stretching the crispy material test piece, thus facilitating observation; during stretching process, the upper pull head and the lower pull head can eliminate the eccentricity of the test piece through small-amplitude rotation during stretching process; therefore, pressure can be converted into pull, thus realizing the direct tensile of the crispy material test piece such as rock and the like.

Description

technical field [0001] The invention belongs to the field of rock mechanics or material testing, and in particular relates to a stick-free pressure-pull conversion device suitable for direct tensile test of brittle material test pieces (rock, concrete, etc.) and a corresponding test method. Background technique [0002] Rock and concrete are common materials in infrastructure construction. Both of these two types of materials have good compressive properties, but they are brittle and low in tensile strength. Therefore, accurate determination of the tensile strength of these materials is extremely important for rationally determining design parameters and avoiding brittle and catastrophic failure of engineering structures. important role. [0003] At present, there are two main types of test methods for determining the tensile strength of rocks: indirect methods and direct methods. The indirect method is to obtain the tensile strength of the tested material indirectly throu...

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Problems solved by technology

[0005] The technical problem to be solved by the present invention is to overcome the shortcomings of the prior art and provide a non-adhesive test device and method for direct tensile tests on rocks. When the connection test is carried out in the connection mode, the defect of test failure is usually caused by insufficient bonding strength, uneven thickness of the adhesive, or peeling of the end; It needs to be bonded with high-strength glue. When the testing machine exerts pressure on the device, the inner bracket and the upper slider closed by welding do not move, and the outer bracket moves downward, driving the lower slider to directly stretch the brittle material sample, which is convenient and intuitive Observation and measurement, during the stretching process, the upper and lower sliders rotate slightly to eliminate the eccentricity of the specimen during stretching

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